How to evaluate the lens of a camera

1. Mechanical structure.

2. Aperture size.

3. Center image quality.

4. Corner picture quality.

5. Distortion control.

6. Vignetting control.

A good shot is good in all these aspects.

1. Wide-angle lens. Traditionally, a wide-angle lens is a lens with a focal length of less than 35mm, such as a 28mm, 24mm, or even 16mm lens. Generally speaking, lenses under 24mm are called ultra-wide-angle lenses.

However, because the vast majority of DSLRs on the market are not full-frame DSLRs, the focal length of the lens must be multiplied by the god model rock or, therefore, for this kind of SLR, 16mm can be counted as a medium ultra-wide-angle lens.

2. Standard lens. Generally speaking, the focal length is 50mm or the angle of view of the lens is closest to the human eye, so it is called a "header". But that's why it's hard to use the header well, because it's not like ultra-wide-angle or macro lenses, which can shoot images that the human eye can't perceive.

The 85mm lens is generally a portrait lens.

3. Medium telephoto lens is generally 100mm or 135mm. Among them, the 100mm lens is generally a macro lens, and the 135mm lens is also a portrait lens, but it focuses on the bust portrait, while the 85mm lens focuses more on the full-body portrait.

There are many criteria for evaluating the quality of a lens:

Workmanship: The workmanship of the lens determines the stable mechanical properties, such as the Sigma 50, although the lens and the overall design are very good, the film is also great, the focal thanks to the large aperture of 77 is also very good, and the sharpness is also very good, but the workmanship is average, and the mechanical properties will decline after a long time. So a lot of old lenses will still be expensive, and the 50 with plastic body and plastic lens is very cheap.

Lens coating technology: The lens should be crystalline, and there is light through, so it is inevitable that the reflection and refraction of light will occur, so high-quality coating technology can alleviate the problems of glare and dispersion caused by this characteristic.

Special technical design (grinding and mounting structure of lens group): Some macro lenses, some switchback lenses or soft focus lenses, etc., are very expensive because they are special and the production process is more complicated. For example, Sony and Minolta's 135 soft focus lenses need to be fitted with 2 apertures.

Macro lenses can focus at very close range, and the structure is completely different from ordinary lenses, so it will be expensive. Some macro lenses also have apertures, which are naturally more expensive.

In its class (with similar focal lengths), a lens with stabilization is more user-friendly than a lens without stabilization, so it's better.

When choosing a lens, or to measure the quality of a lens, there are many entry points, depending on what you are after: some people pursue out-of-focus, so in-focus must be compromised, such as Nikon's 58; Some people want sharpness, and the outburn or color has to be compromised, such as Sigma's 35; Some people pursue large zooms, so the image quality must be compromised, and it will inevitably be inferior to the prime lens; Some people pursue image quality, so the convenience has to be compromised, and they have to move their legs and feet.

In short, the clearest measure of good and bad is**. Expensive nature is a good head

Contrast, sharpness, resolution, bokeh, distortion, optimal aperture, weight, etc.

Sharpness, distortion, dispersion, workmanship, appearance, ease of use.

I don't have an in-depth study of the others, but I don't agree with your statement that [anti-shake has no judgment value]: to make the lens focus and lock the focus quickly when shooting, what does it need to install in the lens? In addition, you can compare and study the two lenses with and without stabilization, and other conditions are the same, **How much is the difference?

You won't say such things that don't have level and technical content.

The lens of a digital camera consists of multiple lenses, and the material is divided into two types: glass and plastic. If the digital camera lens is made of glass, many users and businesses say that the glass lens has good light transmittance and clearer projection images. However, many test reports have shown that glass lenses in glass shooting may not necessarily bring clearer images than plastic materials, and glass lenses may also increase the weight of the camera.

Let's take a look at where the lenses and sensors are placed. As shown in the figure below, the lens assembly from right to left consists of a lens, an electronic shutter, lens group 1, lens group 2, and a CCD. The images taken are projected on the CCD along this optical path.

The focal length adjustment system and shutter system made by Henghe in the assembly are composed of lens group 1 and electronic shutter, which are connected together.

Driven by the motor, the lens group 1 and the electronic shutter can be moved back and forth to adjust the focal length for the sharpest images, controlled by the electronic shutter**. Multiple lenses are used to complete the optical imaging, while the final CCD converts the optical signal into an electrical signal.

It matters, but it doesn't matter.

When it comes to relationships, it is from the perspective of the "camera" as a whole. A camera includes a body and a lens, and a good camera is naturally a combination of a good body and a good lens. Without a good lens, you will definitely not shoot a good **, and you will not be able to talk about a good camera.

To say that it doesn't matter is to say ...... from the abstract "camera".That is, the fuselage. As a DSLR.

For interchangeable lens cameras such as single electrical, the body can indeed be considered separately. The high-quality** body with powerful functions, good handling, and excellent workmanship can indeed be called a "good camera" ......But this has nothing to do with ...... cameraA body of tens of thousands of yuan can also be equipped with a cheap lens ...... of several hundred yuanBut the fuselage is really "good"!

The relationship between the camera and the lens is so complicated, you must know, please protect your camera.